Archive for the ‘laborsaving’ Category

I use an AVR Dragon for most of my simulating/debugging/programming needs. It’s a great tool, but it has a few shortcomings. It comes with an unpopulated Target area where you can supposedly insert an AVR microcontroller and program it without actually being in its native circuit.

Doing so, however, requires that you buy and install a ZIF socket and some male pin headers or female receptacles, and then run a whole mess of jumper wires all over the place.

I hate ratsnests. And I love designing PCBs, and love creating labor-saving tools. So first, I installed the requisite ZIF socket in the target area, and female receptacles in the HVPP and target pin headers, like so:

The new headers don’t help much for ISP programming, but it allows the use of high-voltage programming, if you’re willing to run between 8 and 20 wires between the two receptacles. I thought to myself, “there’s gotta be a better way.”

And here’s what I came up with:

This one is a high-voltage programming adapter for an ATTiny2313. On the underside, it’s just a few pin headers and receptacles:

Given the various socket sizes and pinouts, I needed to create an ISP and a HVP adapter for each socket type and pinout. I have twelve in all. The ISP adapters I call DragonJumpers and the High-Voltage adapters I call DracoDapters. DragonJumpers are on top in the following photo, with DracoDapters below.

I’m a cheapskate. Most of our kits use single-row headers, and it’s cheaper to buy 40-pin headers and break them down to size than buy headers pre-cut. This of course takes time, which is in short supply. And breaking headers apart with a pair of pliers is unreliable and inefficient.

Time to build a machine.

I’ve got a bunch of mediocre tools and a wild mechanical imagination. So I invented a guillotine-like machine with an adjustable stop to get faster, more repeatable results.

You can also watch it in action on youtube. (sorry, couldn’t get the embedding to work on this blog)